Longevity, lifespan, healthspan - any of these sound familiar?
No matter how closely you follow developments in health, these terms have been popularised in books, blogs and podcasts by longevity experts like Petter Attia, David Sinclair and Dr. Mark Hyman.
Lets start with a few definitions.
Longevity can be defined as living a longer healthier life. Increasing life expectancy or 'lifespan', is one part of longevity, i.e. increasing the number of years a person lives from birth until death. The second part is 'healthspan', increasing the length of time a person is healthy - not just alive.
We’re all familiar with the changes that occur as we age, such as wrinkling skin, graying hair, weakening muscles, and deteriorating vision and hearing. Other consequences of aging are less predictable. For example, some people remain mentally sharp well into their 90s, while others start to display signs of dementia in their 60s. Furthermore, research has repeatedly shown how age is a primary risk factor for a number of chronic diseases including cancer, dementia and heart disease.
Understanding aging at the cellular level
In human terms, aging is broadly defined as the progressive deterioration of the physiological and biological functions necessary for survival. Cellular damage that accumulates faster than the body is able to repair it is a primary cause of this deterioration.
Normal cells have a finite lifespan. Cellular aging may occur as a result of continued damage to the cell or as a result of the expression of predetermined information within the cell’s genetic structure. By looking at how individual cells age, we can gain insight into how the body as a whole ages.
Cellular health is regulated by a number of linked processes. Understanding these processes leads to a greater understanding of aging, potentially allowing us to better treat and prevent aging-related degenerative diseases, such as Alzheimer’s and Parkinson’s, and diseases of incorrect senescence or failure to senesce, such as cancer. Ultimately it may enable us to prevent or delay some of the deleterious effects of aging, so we can live longer, healthier lives.
Telomeres and their impact on aging
Telomeres are structures made from DNA sequences and proteins that cap the ends of chromosomes and protect them from getting frayed or tangled, similar to the plastic coating at the end of a shoelace. They play a crucial role in the maintenance of chromosomal stability and in the prevention of chromosomal fusions, which can lead to cancer.
Each time a cell divides, telomeres shorten a little bit. When they get too short, the cell can no longer divide, and it dies. This is called cellular senescence. Short telomeres are therefore a marker of cellular aging.
The natural shortening of telomeres is thought to be one of the reasons we experience health problems as we get older. Studies have shown that telomere length may be a good indicator of how healthy we are, and how long we are likely to live. Shorter telomeres are associated with a number of health problems, including cancer, heart disease, and cognitive decline, and people with shorter telomeres tend to die earlier than those with longer telomeres.
Why do telomeres shorten as we age?
There is some evidence that telomere length can be affected by lifestyle choices. For example, smoking and air pollution have been shown to shorten telomeres, while physical activity and a healthy diet help to preserve telomere length.
Here are some other known contributing factors:
Some genes may increase our risk of telomere shortening.
Our cells produce harmful molecules called free radicals as a by-product of normal metabolism. Environmental toxins such as lead and mercury can also cause free radicals, as can radiation (such as radiation from X-rays). These molecules are unstable and can damage our cells, including our DNA, leading to shortening of our telomeres. Smoking, drinking alcohol, and eating an unhealthy diet can also contribute to oxidative stress.
Inflammation is a natural process that helps our body fight infection and heal wounds. However, inflammation can also cause shortened telomeres, which can lead to damaged DNA. Unhealthy habits like smoking, drinking alcohol to excess, and eating an unbalanced diet that is low in nutrients can all contribute to inflammation, leading to shortened telomeres.
A 2020 study found a link between a diet with a lot of processed food and shorter telomeres. This is likely due to chemicals such as nitrates, which are present in high levels in processed food.
Stress can lead to inflammation, which has been shown to potentially shorten telomeres. Civil servants in highly stressful jobs, and mothers who care for very disabled children and who have high levels of psychosocial stress, have been shown in studies to have very short telomeres and to tend to age faster.
There is currently no cure for telomere shortening, but scientists are working on ways to prevent or reverse it. Lifestyle factors such as physical activity and diet are important factors for stress management. Exercise has been shown to increase telomerase activity and slow the rate of telomere shortening. Diet also has an effect on telomere length. A diet high in fruits and vegetables has been associated with longer telomeres, while a diet high in saturated fat has been associated with shorter telomeres.
In addition, there are a number of supplements that have been shown to preserve telomere length, including antioxidants, omega-3 fatty acids, and probiotics. However, more research is needed to determine their effectiveness conclusively. Before adding a supplement, or making drastic changes, to your diet, it’s always wise to discuss your health goals with your doctor or another healthcare professional.
Telomeres and gene therapy
One possible way to prevent telomere shortening could be through gene therapy that specifically adds new telomeres to our chromosomes. Scientists are looking into whether this is possible and if so whether it would prevent our telomeres from getting shorter as we age and help keep our cells healthy.
Could telomerase be the answer?
Telomerase is an enzyme that maintains the length of telomeres by adding DNA to the ends of chromosomes. Telomerase is why our telomeres continue to grow until we reach puberty, and it is active in stem cells and cancer cells, which is why those cells are able to divide indefinitely.
So could increasing telomerase in the body extend your telomeres? Reduced telomerase activity has been linked to various age-associated diseases, such as heart disease and Alzheimer’s disease, so therapies that increase telomerase activity are a promising approach.
It’s not a good idea to have telomerase switched on all the time, though. If early-stage cancer cells are present, there’s nothing to stop them dividing, and the cancer could spread. In fact, blocking telomerase may help to stop cancer cells from dividing and growing, and drugs that block telomerase are currently being tested as a treatment for cancer.
Telomerase inhibitors may also help to kill cancer cells, and they are being tested in clinical trials for a variety of cancers, including breast, lung, and pancreatic cancer. So far, these trials have been successful, so telomerase inhibitors may soon become a common treatment for cancer.
The role of genetics in longevity
The results of ongoing studies demonstrate that familial background, early-life conditions, and midlife environment or lifestyle factors play an crucial role in human longevity. In one study, parental longevity turned out to be one of the strongest predictors of survival to age 100. This study also suggested that a significant portion of the lifespan advantage that siblings of centenarians have may be related lifestyle factors and living conditions, rather than genetic factors alone.
A few of the common variations, called polymorphisms, associated with long lifespans are found in the APOE, FoxO3, and CETP genes, but they are not found in all individuals with exceptional longevity. It is likely that variants in multiple genes, some of which are unidentified, act together to contribute to a long life.
Some of the gene variants that contribute to a long life are involved with the basic maintenance and function of cells. These cellular functions include DNA repair, telomere maintenance, and protection of cells from free radical damage.
Other genes that are associated with blood fat (lipid) levels, inflammation and the cardiovascular and immune system contribute significantly to longevity because they reduce the risk of stroke, insulin resistance, and heart disease, which is the main cause of death in older people.
Lifestyle choices for a longer fulfilling life
Genetics, lifestyle, and environment each play a part in aging, but it’s the combination of all three factors that determine healthy longevity. We all have to accept the genetics we've been dealt with, but we can influence the other two factors.
The importance of adopting a holistic approach that implements science-backed strategies for longevity cannot be emphasized enough. A balanced diet, with limited processed food, is important, as is regular exercise, stress management with mindfulness practices and healthy sleep patterns.
A 2015, meta-analysis with 3.4 million global participants, researched the association between loneliness, social isolation and mortality risk.
This study found that loneliness can lead to a 26 percent higher chance of early death in initially healthy individuals. Social isolation and living alone are linked to even higher risks of premature mortality, with increases of 29 percent and 32 percent respectively - social connections, and strong relationships play a critical part in increasing life expectancy.
Health data & longevity
Recognizing the role of lifestyle factors in increasing longevity, there has been an explosion of longevity-focused companies designed to help people lead healthier lives and avoid the onset of chronic diseases.
At Vital, we help longevity companies access the key biomarkers they need to build a picture of a person's overall health and develop personalized, preventative treatment plans.
Using our wearables API, longevity companies have been able to instantly access real-time data from users' wearables across biomarkers like sleep, nutrition or heart rate. Knowing the value of lab testing to test for biomarkers like cholesterol, they've used our APIs to launch lab testing across 50 states in a matter of weeks.
If you’re looking to access compliant health data from wearables and lab testing, book a demo with our team to learn more!